金属材料弹性模量的测量精度受很多试验因素的影响，将挤压成型的7N21铝合金加工成圆棒试样，采用静态拉伸试验方法测量了其弹性模量，并对控制模式、引伸计的使用及预拉伸对弹性模量测量的影响进行了分析。结果表明：弹性模量测量精度受控制模式与试样预拉伸的影响较小，主要由引伸计的选择与使用决定。采用单个引伸计测量同一试样多个方向上的弹性模量值并取平均值的方法可以有效消除偏心拉伸的影响，能够提高测量结果的准确性和稳定性。

The measurement accuracy of elastic modulus of metal materials is affected by many experimental factors. In this paper, 7N21 aluminum alloy was processed into a round bar sample, and its elastic modulus was measured by static tensile test method. The influence of control mode, the use of extensometer and pretension on the measurement of elastic modulus was analyzed. The results show that the measurement accuracy of elastic modulus is less affected by the control mode and specimen pretension, which is mainly determined by the selection and use of extensometer. Using a single extensometer to measure the elastic modulus of the same sample in multiple directions and take the average value can effectively eliminate the influence of eccentric tension, and can improve the accuracy and stability of the measurement results.